hey dear
look
neither of the ways you mentioned is the right answer
you say everything IS right... the 'S' you wrote at the end of the word is a verb my sister, it's not part of the word
and in informal speech we say everything's right... I think that's why you're confused.. and I believe that's because you've only heard the word being spoken, not read it
you see the word 'everything' is not plural.. you're talking about every SINGLE thing... not about all the things together
so you use IS not ARE
I'm not so good at teaching I know... but I hope you understood what I wanted you to know
take care
peace